Which changes involve forming or breaking chemical bonds?

A.burning and digesting

B.boiling and melting

C.burning and melting

D.rusting and cutting

Number of Br atoms : 2.679 x 10²³

The mole is the number of particles contained in a substance

1 mol = 6.02.10²³

Moles can also be determined from the amount of substance mass and its molar mass

[tex]\tt mol=\dfrac{mass}{MW}[/tex]

Proust stated the Comparative Law that compounds are formed from elements with the same Mass Comparison so that the compound has a fixed composition of elements

[tex]\tt mass~Br=\dfrac{2.Ar~Br}{MW~CH_2Br_2}\times mass~CH_2Br_2\\\\mass~Br=\dfrac{2.80}{174}\times 38.7=35.59~g[/tex]

[tex]\tt \dfrac{35.59}{80}=0.445[/tex]

[tex]\tt 0.445\times 6.02\times 10^{23}=\boxed{\bold{2.679\times 10^{23}}}[/tex]

Answer:

C6H12O2

Explanation:

The first step in accurately deducing the structure/formula of the model is to count the number of carbon atoms, hydrogen atoms and oxygen atoms mentioned in the model. This gives the molecular formula of the compound.

Next, you look at there arrangement of atoms and bonds as stated in the model, this tells us the structure of the molecule and confirms the molecular formula initially deduced.

The structure of the compound is shown below.

Answer:

Your answer would be C6H12O2

Explanation: I hope I helped you :)

Answer:

E. A conductor is needed for electricity to flow in a circuit.

Explanation:

Electric current can flow without a resistor, as in short circuit.

A short circuit is an electrical circuit that allows a current to travel along an unintended path with no or very low electrical impedance.

Without a switch, electricity can flow in a circuit, switch is only used to close or open the circuit.

Thus, the only correct option is  E

E. A conductor is needed for electricity to flow in a circuit.

Answer:

Explanation:

The distance covered by an object given it's velocity and time taken can be found by using the formula

From the question

velocity = 35.0 mi/hr

time = 2455 s = 0.68 hr

We have

distance = 35 × 0.68

We have the final answer as

Hope this helps you

Answer:

I'm confused on what u need us to answer

Answer:

The age of the earliest known human-like footprints is approximately 3000000 years.

Explanation:

Decay of isotopes is represented by the following ordinary differential equation:

[tex]\frac{dm}{dt} = -\frac{m}{\tau}[/tex] (Eq. 1)

Where:

[tex]\frac{dm}{dt}[/tex] - First derivative of mass with respect to time, measured in miligrams per year.

[tex]m[/tex] - Current mass of the isotope, measured in miligrams.

[tex]\tau[/tex] - Time constant, measured in years.

Now we proceed to obtain the solution of the differential equation:

[tex]\int\limits {\frac{dm}{m} } = -\frac{1}{\tau}\int dt[/tex]

[tex]\ln m = -\frac{t}{\tau}+C[/tex]

[tex]m(t) = e^{-\frac{t}{\tau}+C }[/tex]

[tex]m(t) = m_{o}\cdot e^{-\frac{t}{\tau} }[/tex] (Eq. 2)

Where:

[tex]m_{o}[/tex] - Initial mass of the isotope, measured in miligrams.

[tex]t[/tex] - Time, measured in years.

[tex]\tau[/tex] - Time constant, measured in years.

We proceed to clear time within the formula presented above:

[tex]\ln \frac{m(t)}{m_{o}} = -\frac{t}{\tau}[/tex]

[tex]t = -\tau \cdot \ln \frac{m(t)}{m_{o}}[/tex]

In addition, time constant can be found as a function of half-life:

[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex] (Eq. 3)

If we know that [tex]t_{1/2} = 500000\,yr[/tex], [tex]m_{o} = 8\,mg[/tex] and [tex]m(t) = 0.125\,mg[/tex], the age of the earliest known human-like footprints is:

[tex]\tau = \frac{500000\,yr}{\ln 2}[/tex]

[tex]\tau \approx 721347.520\,yr[/tex]

[tex]t = -(721347.520\,yr)\cdot \ln \left(\frac{0.125\,mg}{8\,mg} \right)[/tex]

[tex]t \approx 3000000\,yr[/tex]

The age of the earliest known human-like footprints is approximately 3000000 years.

Answer:

Candle wax will melt to a liquid and burn as a gas. Only covalent compounds can be liquid or gas!

Explanation:

Question: Is Wax Ionic Or Covalent? - Ceramicsexpandusceramics.com

In the given question, wax is a covalent compound because it is composed of nonmetal atoms that share electrons to create covalent bonds.

Covalent compounds are formed when two or more nonmetal atoms share electrons in order to achieve a stable electron configuration.

Therefore, wax is a covalent compound because it is made up of non-metal atoms sharing electrons to form covalent bonds.

Learn more about covalent compounds here:

https://brainly.com/question/11632372

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Answer:

a

Explanation:

Answer:A. When particles transfer energy by touching.

Example: After a car is turned on, the engine becomes hot.

Answer:

He and Ar

Explanation:

Answer:

Friction

Explanation:

Energy is lost to heat as the object overcomes kinetic friction as it slides up the ramp. The energy loss is equal to the work done by the friction force.

Answer:

It would be compound.

Explanation:

It is this way because if it adds another proton it becomes more positive that nuetral, and if you add an electron it just makes the atom more dense. That is why the answer is compound. Hope this helped :)

Answer:

158.17

Explanation:

divide the given mass by the molar mass

Answer:

it is aluminum (Al)

Explanation:

Answer:

the core

Explanation:

Answer:

3rd option, the core.

Explanation:

Answer:

30

Explanation:

its pushed into a 30 resistor

Hope this is your answer i wasn't able to see he full question so i am not sure

Answer: A.En Hedu'Anna

Answer:

En Hedu’Anna!

Explanation:

Answer:

Equation:

Q = m•C•ΔT

Answer:

The goal of science is to learn how nature works by observing the natural and physical world, and to understand this world through research and experimentation.

Explanation:

Answer:

difficile infection. By reintroducing a healthy diversity of bacteria, fecal transplantation can re-establish colonization resistance to prevent C. difficile from gaining a foothold and becoming a dominant organism in the environment of the gut.

Explanation:

Answer:

Mg[tex]^+2[/tex]

Explanation:

Es el elemento que buscas.

Answer:

A mixture is a substance of different things combined together.

Explanation:

Hope this Helps!

Answer:

As the number of atoms in the reactants side is equal to the number of atoms in the product side, the reaction is balanced

Two hydrogen molecules per oxygen molecule are produced because water (H2O) has a ratio of two hydrogen atoms to one oxygen atom. A decomposition reaction occurs when one reactant breaks down into two or more products. This can be represented by the general equation: AB → A + B.

H2O is the chemical formula of water. It means that each molecule of water is made up of two hydrogen atoms, indicated by the letter H, and a single oxygen atom, represented by the letter O. Water is chemical substance with no smell, taste or color.

Answer:

The answer is D, ductility

Explanation:

The definition of ductile is "(of a metal) able to be drawn out into a thin wire."

Answer:

3

Explanation:

3 ampers (it says in the problem)

Answer:

I think the answer is true

Answer:

Mg with 2 dots

Explanation:

Mg: as the valnce shell of Mg has 2 electrons only

presented by 2 dots

Answer:

1.5 x 10⁵

Explanation:

Scientific notation always starts in the 1's place (1.)

Answer:

Its going to be D) In sigma bonds the electrons are in the space between the joined atoms and pi bonds above and below the joined atoms